rudy, what can you tell us? >> reporter: they are doing a security sweep and the campus remains locked down. it will remain locked down for the next several hours. they hope to open up the north cam us in an hour or so. they are searching for that possible second gunman. they are getting conflicting information about this possible suspect, a man who walked on campus dressed in black, armed with an ak-47, walking down the street directly behind me, then walking down in front of a large dormitory across the street from the mainly prairie on campus. -- from the main library. all the students that were there as they were starting the school day scattered, sought cover. then we are told the gunman walked into the library and took his own life. because there are different descriptions on the suspect, some saying he wore all black, some saying he had a brown jacket wearing a hoodie, a ski mask, law enforcement officers want to make sure they have only a lone gunman. if there is a possibility of a second gunman they wan